Is it possible for a chemical pregnancy (with the fetus "aborting" itself around 4 weeks-- when i tested) to cause a longterm hormone imbalance?

Unlikely: If you are no longer testing pregnant, its unlikely that the miscarriage of such an early pregnancy would have any long-term effects. There are some rare problems that can happen after a miscarriage such as gestational trophoblastic diseas and a cancer called choriocarcinoma. But both of these produce pregnancy hormone and can be ruled out with a simple blood pregnancy test. Best wishes!